Question

a) Calculate the distance at which an
obiect should be placed in front of
La convex dens of focal length loom.
to obtained a virtual image double
of its size.
b) in the above given case find the
magni fication if image formed is
real. Express it on torms of relation
between Nandu.

Answer 1

Answer:

a.)

u = -50 m

v = -100 m

b.)

m = +2 = v/u

Explanation:

f = + 100 m

m = + 2 (because a virtual image is required and of double size)

m = v / u

2 = v / u

v = 2u

By lens formula,

1/f = 1/v - 1/u

1/100 = 1/2u - 1/u = 1-2/2u

1/100 = -1/2u

u = -100/2

u = -50 m

v = 2 * -50 = -100 m